Maxwell and the speed of light

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Discussion Overview

The discussion revolves around the historical context and implications of Maxwell's equations regarding the speed of light and the concept of aether. Participants explore whether Maxwell anticipated the constancy of the speed of light for all observers and how Einstein's interpretations differed from earlier theories.

Discussion Character

  • Debate/contested
  • Historical
  • Conceptual clarification

Main Points Raised

  • Some participants assert that Einstein was the first to claim the speed of light is constant for all observers, while others argue that Maxwell's equations already implied this constancy.
  • One participant notes that during Maxwell's time, the constancy of light's speed was viewed as a flaw in the theory, suggesting that it would need modification.
  • There is a discussion about Maxwell's belief in the luminiferous aether as a medium for electromagnetism, with some participants questioning whether he actually proposed its existence or merely used it as a conceptual tool.
  • Another participant mentions Lorentz's theory, which maintained the concept of aether while proposing that the speed of light is invariant.
  • Some participants express skepticism about the relevance of aether in modern physics, stating it does not fit with current observations, while others bring up dark matter and its detection challenges.
  • References to Maxwell's 1873 paper are made, highlighting the aether's role in the propagation of electromagnetic waves.

Areas of Agreement / Disagreement

Participants do not reach consensus on whether Maxwell recognized the constancy of the speed of light or the necessity of aether. Multiple competing views exist regarding the historical interpretation of these concepts and their implications for modern physics.

Contextual Notes

Some claims about Maxwell's views on aether and the implications of his equations are based on interpretations that may vary. The discussion reflects differing opinions on the historical context and the evolution of theories surrounding electromagnetism and the speed of light.

genefalk
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Einstein said that the speed of light is constant for all observers.

When Maxwell derived that the speed of light in the ether was 299,792,458 m/s could he or did he surmise that the speed of light is constant for all observers (regardless of the motion of the source)?
 
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genefalk said:
Einstein said that the speed of light is constant for all observers.

When Maxwell derived that the speed of light in the ether was 299,792,458 m/s could he or did he surmise that the speed of light is constant for all observers (regardless of the motion of the source)?
No, it took Einstein to make that leap.
 
phinds said:
No, it took Einstein to make that leap.

I'm not sure that's exactly true. It was well known by Einstein's time that Maxwell's equations predicted that speed of light is constant independent of the motion of the source. This was generally thought of as a flaw in the theory and that Maxwell's equations were approximate and would need to be modified. Einstein's contribution was to take this feature seriously.
 
Maxwell thought electromagnetism was carried in some kind of luminiferous aether. I suppose it was understood that the speed of light would be relative to the aether. Lorentz eventually came up with a theory in which the speed of light was invariant, but still held on to the concept of aether.
 
We are done with aether now, it does not fit with observation.
Dark matter is what though?, not aether but it is there (apparently)
 
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Khashishi said:
Maxwell thought electromagnetism was carried in some kind of luminiferous aether. I suppose it was understood that the speed of light would be relative to the aether. Lorentz eventually came up with a theory in which the speed of light was invariant, but still held on to the concept of aether.
May be wrong but not certain that Maxwell did suppose the existence of an aether. He produced equations which fit the facts by postulating a mechanical analogue using rotating cells. He did not seem to propose an actual mechanism for EM phenomena.
 
tech99 said:
May be wrong but not certain that Maxwell did suppose the existence of an aether. He produced equations which fit the facts by postulating a mechanical analogue using rotating cells. He did not seem to propose an actual mechanism for EM phenomena.

Maxwell worked a lot in the aether theory. In his 1873 paper "Treatise on Electricity and Magnetism" aether is mentioned as the medium in which EM waves and light propagate. But even at that time the properties of aether were considered sort of magical.

from Wikipedia: https://en.wikipedia.org/wiki/Luminiferous_aether

Wikipedia said:
the aether was hypothesized as the absolute and unique frame of reference in which Maxwell's equations hold. That is, the aether must be "still" universally, otherwise c would vary along with any variations that might occur in its supportive medium. Maxwell himself proposed several mechanical models of aether based on wheels and gears..
 
Vanadium 50 said:
I'm not sure that's exactly true. It was well known by Einstein's time that Maxwell's equations predicted that speed of light is constant independent of the motion of the source. This was generally thought of as a flaw in the theory and that Maxwell's equations were approximate and would need to be modified. Einstein's contribution was to take this feature seriously.
Right. That's the "leap" that I was talking about. Maybe it's just me but I've always thought that THAT leap was the hard one and the one he didn't make (that the universe wasn't static) would have been an easier one. I mean, to me the speed of light thing is just weird and it astounds me that anyone could make that leap. 'Course I couldn't have made either one of them I'm sure.
 
There have also been many similar discussions in the forum. Take a look at (search results):
https://www.physicsforums.com/search/2848416/?q=Maxwell+and+the+speed+of+light&t=post&o=relevance&c[title_only]=1

All (or many) similar, relevant and enlightening [PF discussions].

+ see bottom of this page.
 
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  • #10
rootone said:
We are done with aether now, it does not fit with observation.
Dark matter is what though?, not aether but it is there (apparently)
None of these fit the observation [yet] (even the LUX experiment for detecting dark matter is failing, even after reaching its maximum resolution). There are also Einstein-aether theories for dark energy, but they are also failing.
Aether was abandoned after the Michelson-Morley experiment ...
 
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